1. Field of the Invention
The present invention relates in general to a four-wheel drive vehicle derived from a transversely mounted front engine-front drive system and more particularly to a steering gear rack and transfer pinion arrangement for such a four-wheel drive vehicle.
2. Description of the Prior Art
An example of a prior art steering gear rack and transfer pinion arrangement for a four-wheel drive vehicle of the above described kind is shown in FIG. 3. In this arrangement, a steering gear rack 10 is disposed lower than an axis L1 of a transfer ring gear 12 and an axis L2 of a transfer pinion 14 or a propeller shaft 16. The axes L1 and L2 are disposed at substantially the same level or the same height-above-the ground. L3 is a level representing an upper termination of a ground clearance of a front suspension lower control arm 18. 16a and 16b indicate a front pivot and rear pivot of the lower control arm 18, respectively.
Another example of a prior art steering gear rack and transfer pinion arrangement is shown in FIG. 4. In this arrangement, the axis L2 of the transfer pinion 14 or propeller shaft 16 is disposed lower than the axis L1 of the transfer ring gear 12, i.e., the axis L2 is offset dowardly from the axis L1 by a distance .alpha.1.
A problem of the arrangement of FIG. 3 is that due to the disposition of the steering gear rack 10 at a location lower than the axes L1 and L2, an engine (not shown), transaxle 20, etc. are necessarily disposed at high levels-above-the ground, i.e., necessarily disposed to have large ground clearances, resulting in the necessity of disposing a hood at a correspondingly high level-above-the ground.
This problem can be solved by the arrangement of FIG. 4. However, this arrangement is disadvantageous since due to the disposition of the steering gear rack 10 above the propeller shaft 16, it causes a large roll steer, thus deteriorating the steering characteristics and therefore the running stability of the vehicle.